Process for the destructive distillation of wood



June 29,1926. 1,590,901

J. S. MORGAN PROCESS FOR THE DESTRUCTIVE DISTILLATION OF WOOD Filed Oct. 1, 1921 Mrnez:

Patented June 29, 1926.

UNITED STATES ENGLAND.

PATENTOTOEFICE.

- JOHN STANLEY MORGAN, OF LONDON, ENGLAND, ASSIGNOR T0 THERMAL INDUS- TRIAL AND CHEMICAL (T. I. 0.) RESEARCH COMPANY, LIMITED, OF LONDON,

PROOESSFOR THE DESTRUCTIVE DISTILLATION OF WOOD.

Application filed October 1., 1921, Serial No. 504,711, and in Great Britain November 2, 1920.

My invention relates to a process for dedistil wood in a finely subdivided state by ordinary methods, because at a certain stage in the process, exothermic changes occur, which cause the temperature to rise so rapidly that there is a partial destruction of the valuable products.

By the present invention, subdivided wood is destructively distilled by conducting the heating in presence of molten metal which is of such mass relatively to the mass of wood undergoing treatment that the temperature of the distillation remains substantially constant notwithstanding the heat evolved by exothermic reactions occurring during the distillation. The yield of volatile products is thereby increased.

Preferably the finely subdivided wood, for instance saw-dust or shavings, is caused to pass at a suitable rate through a bath of molten lead and maintained at a temperature of 350 C. The rate depends on the amount,

of moisture in the wood. A suitable mode of causing the travel through the metal is by carrying the material beneath the normal surface of the molten metal by means of a surface not wetted thereby and travelling into the molten metal through the surface of the latter, as described in the specification to United States patent application Serial No. 490,650, filed Aug. 8, 1921, patented May 5, 1925, No. 1,536,908, and preferably in the form of still described in the said specification and illustrated in Fig. 1 of the accompanying drawings, representing a vertical cross section through the still. a is a rectangular box having a cover 5 provided with a vapour outlet 0. The ends of the still carry bearings for the shafts of drums or turnover wheels d. Round these drums an endless belt 6 travels in the direction of the arrow. The still contains molten metal, in this case lead, to the level 7 and is kept-at a temperature of 350 C. by any suitable mode of heating. The subdivided wood enters the still through the gas-tight feed 9, and is carried as a thin layer between the lower run of the belt and the molten metal and becomes carbonized; the vapours and gasses escape around the ed es of the band and leave the still through tlie outlet 0 whilst charcoal is delivered on to the surface of the metal and is removed by means of the gas-tight discharge h, a scraper i ensuring removal of any ma terial adhering to the surface of the belt.

I Having thus described the nature of the said invention and the best means I know of carrying the same into practical effect, I claim I 1. A process of destructively distilling wood, which consists in subdividing the wood and distilling it in contact with molten metal which is of such mass relative to the mass of wood undergoing treatment that the temperature of the distillation remains substan tially constant notwithstanding the heat evolved by exothermic changes occurring during the distillation.

v 2. A process of destructively distilling wood, which consists. in finely subdividing the wood, and causing it to travel in the form of a layer in contact with molten metal which is of such mass relative to the mass of wood undergoing treatment that the temperature of the distillation remains substantially constant notwithstanding the heat evolved by exothermic changes occurring during the distillation.

3. A process of destructively distilling wood, which consists in finely subdividing the wood and causing it to travel through molten metal in the form of a layer. between a surface travelling beneath the surface of the metal and the molten metal, which latter is of such mass that a substantially constant temperature of 350 C. is maintained notwithstanding the heat evolved by exothermic changes occurring during the distillation.

Intestimony whereof I have signed my name to this specification.

JOHN STANLEY MORGAN. 

